The invention relates to a cooling device for an internal combustion engine, having a radiator through which a coolant flows, and with at least one cooling air blower and an airflow guide housing disposed between the radiator and the cooling air blower.
A radiator through which a coolant flows and which is cooled by the cooling air supplied by a cooling air blower is associated with an internal combustion engine as a rule. An airflow guidance housing disposed between the radiator and the cooling air blower is used to guide the air.
Because of restricted space conditions, quite often the cooling air blower is disposed asymmetrically in respect to the radiator, such as is disclosed, for example, in German Patent Publication DE 38 22 052 A1. The result is a greatly varied supply of different areas of the radiator with the cooling air flow forced by the cooling air blower and the airflow guide housing. To even out the flow it is proposed to provide an additional interior housing inside the airflow guide housing which divides the aspiration area of the cooling air blower, so that various areas of the radiator are supplied with different cooling air flows.
In a cooling installation in accordance with German Utility Model DE-GM 66 06 723 for a locomotive, the heat exchangers have been moved so close to a cooling air blower, again because of restricted space conditions, so that cooling air does not flow in equal amounts through all surface areas of a heat exchanger, particularly the one located on the pressure side. To even out the flow-through, this heat exchanger is equipped with cooling segments, which have great flow-through resistance.
Shutters disposed in the arch of the roof of the locomotive have no effect on the flow in the heat exchanger.
It is an object of the invention to increase the cooling output of heat exchangers for internal combustion engines by making the cooling air flow more even.
It is not possible to increase the cooling output of a heat exchanger arbitrarily by increasing the conveying output of a cooling air blower because, once a defined limit speed of the flow has been exceeded, the exchange ratio of a heat exchanger falls off again. An increase in the cooling output can be obtained by evening out the cooling air flow, i.e. a flow covers all areas of the radiator with optimum speed.
This is attained in accordance with an embodiment of the invention in that in areas close to the cooling air blower, where high flow speeds are expected, the flow resistance of the radiator is increased in respect to areas where the flow is slower because they are remote from the cooling air blower.
In accordance with another embodiment of the invention, different flow resistances in different cooler areas are generated by different spacing of cooling fins. The cooling fins in areas close to the cooling air blower are disposed closer together than in the areas remote from the cooling air blower.
In accordance with still another embodiment of the invention, the cooling air is laterally deflected in the airflow guide housing after flowing through the radiator. It is advantageous here to embody the half of the radiator which is close to the cooling air blower with closely spaced cooling fins and the half of the radiator which is remote from the cooling air blower with widely spaced cooling fins in order to obtain an evening out of the flow.
In accordance with yet another embodiment of the invention, the desired flow resistance is obtained by a flow grating disposed on the radiator in the cooling air flow, wherein the flow resistance of the flow grating is made greater in the areas of the radiator which are close to the cooling air blower than in the zones remote from the cooling air blower. An evening out of the flow is also achieved by means of this arrangement, so that the output of the radiator can be better utilized.
In accordance with a further embodiment of the invention, segments are provided in the flow grating which are closer together in the zones with higher flow resistance than in zones of low flow resistance.
In accordance with another embodiment of the invention the radiator is disposed on the aspirating side.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.